JPH1036639A - Epoxy resin composition for laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin compsn. for laminates which gives a prepreg hardly discoloring to yellowish brown without degrading the heat resistance of a laminate obtd. therefrom by adding a specific antioxidant to a compsn. contg. a specific epoxy resin, a specific phenolic compd., a curative, and a cure accelerator. SOLUTION: A specific compd. is added as the antioxidant to a substantially solventless epoxy resin compsn. for laminates contg. an epoxy resin having on average at least two epoxy groups in the molecule, a phenolic antioxidant having at least two phenolic hydroxyl groups in the molecule, a curative, and a cure accelerator. Eight compds. (from a to h) can be used here as the antioxidants, examples being represented by formulas 1 and II.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition used for a copper-clad laminate or the like.

[0002]

2. Description of the Related Art Conventionally, a prepreg is manufactured by impregnating a base material such as a glass cloth with an epoxy resin composition and then drying and semi-curing an epoxy resin laminate used for manufacturing a printed wiring board. A required number of such prepregs are stacked, and a metal foil such as a copper foil is arranged on one side or both sides of the prepreg as necessary, and then laminated, and then heated and pressed. The epoxy resin composition generally contains a solvent to adjust the viscosity so as to have a viscosity suitable for impregnating the inside of the base material.

However, when using an epoxy resin composition whose viscosity is adjusted by containing a solvent, there is a problem in terms of working environment and energy cost because a large amount of the solvent is used. Therefore, for example, as shown in JP-B-60-39288, an epoxy resin having an average of two or more epoxy groups in a molecule, a phenolic compound having two or more phenolic hydroxyl groups in a molecule, a curing agent, A method has been proposed in which a prepreg is produced using a substantially solvent-free epoxy resin composition containing a curing accelerator and the prepreg is heated and pressed to produce a laminate.

However, if a prepreg is to be produced by a method as shown in Japanese Patent Publication No. 39288/1985, the resulting prepreg may turn yellow-brown and pose a problem in appearance.

[0005] With the recent increase in the mounting density of printed wiring boards, a laminate having excellent heat resistance has been demanded.
Therefore, an epoxy resin composition for a laminated board is desired in which the obtained prepreg does not easily turn yellow-brown without lowering the heat resistance of the obtained laminated board.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an epoxy resin having an average of two or more epoxy groups in a molecule; A substantially solvent-free epoxy resin composition for a laminate comprising a phenolic compound having two or more phenolic hydroxyl groups in a molecule, a curing agent, and a curing accelerator, wherein the resulting laminate has a heat resistance An object of the present invention is to provide an epoxy resin composition for a laminated board, from which a prepreg which does not easily turn yellow-brown without lowering the properties can be obtained.

[0007]

The epoxy resin composition for laminated boards according to claim 1 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule. A phenolic compound having at least one
A substantially solvent-free epoxy resin composition for a laminate containing a curing agent and a curing accelerator, wherein the epoxy resin composition also contains a compound represented by the following formula (a). And

[0008]

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The epoxy resin composition for a laminate according to claim 2 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (b): It is characterized by containing a compound.

[0010]

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The epoxy resin composition for a laminate according to claim 3 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent and a curing accelerator, the epoxy resin composition is represented by the following formula (c). It is characterized by containing a compound.

[0012]

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The epoxy resin composition for a laminate according to claim 4 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (d). It is characterized by containing a compound.

[0014]

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The epoxy resin composition for a laminate according to claim 5 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent and a curing accelerator, the epoxy resin composition is represented by the following formula (e). It is characterized by containing a compound.

[0016]

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The epoxy resin composition for a laminate according to claim 6 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (f). It is characterized by containing a compound.

[0018]

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The epoxy resin composition for a laminate according to claim 7 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (g): It is characterized by containing a compound.

[0020]

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The epoxy resin composition for a laminate according to claim 8 of the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (h): It is characterized by containing a compound.

[0022]

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According to a ninth aspect of the present invention, in the epoxy resin composition for a laminate according to any one of the first to eighth aspects, the curing agent is dicyandiamide. It is characterized by.

The compounds represented by the above formulas (a) to (f) are compounds which are generally used as an antioxidant, and are generated by heating during the production of a prepreg by acting as the antioxidant. It is thought that oxidization of the resin component is suppressed, and a prepreg that does not easily turn yellow-brown can be obtained. The compounds represented by the formulas (a) to (h) are compounds among the antioxidants that are unlikely to decrease the heat resistance of the obtained laminated board.
Without lowering the heat resistance of the resulting laminate, the resulting prepreg is less likely to turn yellow-brown.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin composition for a laminate according to the present invention comprises an epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic compound having two or more phenolic hydroxyl groups in a molecule. And a curing agent, a curing accelerator, and at least one compound selected from the group represented by the above formulas (a) to (h). .

The epoxy resin used in the present invention includes:
Any epoxy resin having an average of two or more epoxy groups in one molecule may be used. For example, bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolak epoxy resin, bisphenol A novolak epoxy Resins, cresol novolak-type epoxy resins, diaminodiphenylmethane-type epoxy resins, and epoxy resins that are flame-retarded by partially halogenating some of the hydrogen atoms in these epoxy resin structures, etc. alone, modified products, and mixtures. .

In addition, 2 parts by weight in 100 parts by weight of the epoxy resin
In the case of an epoxy resin containing 50 parts by weight or more of a liquid epoxy resin having a viscosity at 5 ° C. of 1,000 to 30,000 cps, the obtained prepreg has excellent resin impregnation properties,
In addition, a prepreg having a desired resin adhesion amount is easily obtained, which is preferable.

The phenolic compound used in the present invention is:
Any phenolic compound having two or more phenolic hydroxyl groups in one molecule may be used, and examples thereof include bisphenol A, bisphenol F, phenol novolak, cresol novolak, pyrogallol, and these phenolic compound structures. A single, modified, or mixture of a phenolic compound or the like which has been made flame-retardant by partially halogenating a hydrogen atom can be used.

The curing agent used in the present invention is not particularly limited. For example, amide curing agents such as dicyandiamide and aliphatic polyamide, amine curing agents such as aromatic amines, diaminomaleonitrile and And hydrazide compounds and acid anhydrides, and these can be used in combination.

When dicyandiamide is contained as a curing agent, the storage stability of the obtained prepreg and the heat resistance of the obtained laminated board are excellent and preferable.

The curing accelerator used in the present invention is not particularly limited. For example, imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole and 2-phenylimidazole; Diaza
Tertiary amines such as bicyclo [5.4.0] undecene-7, triethylenediamine, benzyldimethylamine;
Tributylphosphine, organic phosphines such as triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylboron salts such as triphenylphosphinetetraphenylborate and the like can be exemplified,
These may be used alone or in combination of two or more. Usually, the content of the curing accelerator is preferably about 1 part by weight or less based on 100 parts by weight of the epoxy resin composition.

The epoxy resin composition of the present invention needs to contain at least one compound selected from the group represented by the above formulas (a) to (h). In addition,
In the formulas (a) to (c) and (e) to (h), t-Bu represents a tertiary butyl group. From the above equations (a) to (f)
The compound represented by is a compound generally used as an antioxidant, and by the action of this antioxidant, oxidation of a resin component generated by heating at the time of prepreg production is suppressed, and the color changes to yellow-brown. It is considered that a prepreg that is difficult to be obtained is obtained. In addition, the compounds represented by the above formulas (a) to (h) are compounds among the antioxidants that are unlikely to lower the heat resistance of the obtained laminate. Therefore, when the epoxy resin composition also contains at least one compound selected from the group represented by the formulas (a) to (h), the heat resistance of the obtained laminate is not reduced. In addition, the resulting prepreg is less likely to turn yellow-brown. The compounds represented by the formulas (a) to (h) may be used in combination.

The compounds represented by the above formulas (a) to (h) are, among the components of the epoxy resin composition, an epoxy resin having an average of two or more epoxy groups in a molecule;
A phenolic compound having two or more phenolic hydroxyl groups in the molecule, a curing agent, a curing accelerator,
From 0.2 to 6 parts by weight per 100 parts by weight of the compound represented by the formula (h). If the amount is less than 0.2 parts by weight, the resulting prepreg may turn yellow-brown, and if it exceeds 6 parts by weight, the heat resistance of the resulting laminate may decrease.

The epoxy resin composition of the present invention includes:
If necessary, an inorganic filler, a flame retardant and the like can be contained.

The epoxy resin composition of the present invention comprises: an epoxy resin having an average of two or more epoxy groups in the molecule; a phenolic compound having two or more phenolic hydroxyl groups in the molecule; A curing accelerator, at least one compound selected from the group represented by the above formulas (a) to (h), and the like are heated and melted if necessary, and then mixed to produce.

All of these may be mixed at the same time, but an epoxy resin having an average of two or more epoxy groups in a molecule or a phenolic compound having two or more phenolic hydroxyl groups in a molecule is preferred. Part of the blending amount, a curing agent and a curing accelerator, a first mixture of both or each alone, and the epoxy resin and the phenolic compound excluding the blending amount used in the first mixture,
At least one compound selected from the group represented by the above formulas (a) to (h) is heated, melt-mixed to form a second mixture, and then the first mixture and the second mixture are mixed. You may make it. In the case of the method of mixing after forming the first mixture and the second mixture, since the curing does not easily proceed when the epoxy resin and the phenolic compound are melted and mixed, it is possible to mix at a high temperature, that is, at a low viscosity. It is possible to mix uniformly, and the quality of the obtained prepreg becomes uniform, which is preferable.

When the epoxy resin and the phenolic compound are melt-mixed, at least one compound selected from the group represented by the above formulas (a) to (h) is blended and then melted. When mixed, the effect of suppressing discoloration of the obtained prepreg is particularly excellent and preferable.

The epoxy resin composition obtained in the present invention is impregnated into a substrate and dried by heating to produce a prepreg. As the substrate, although not particularly limited, glass fiber, aramid fiber, polyester fiber, cloth using fibers such as nylon fiber, mat or nonwoven fabric or kraft paper,
Paper such as linter paper can be used. The conditions for heating and drying are not particularly limited, and drying is performed under the condition that the epoxy resin composition is semi-cured.

The method of impregnating the base material with the epoxy resin composition is not particularly limited, and examples thereof include a dipping method, a roll coater method, and a die coater method. In the case of a die coater method in which a substrate is applied to one surface of a substrate using a die coater and then impregnated by heating, the prepreg having excellent resin impregnation properties and a desired resin adhesion amount is preferably obtained. The amount of resin to be impregnated is
Although not particularly limited, when the content is 30 to 60% by weight, the heat resistance and thickness deviation of the obtained laminated board are excellent and preferable.

[0040]

【Example】

(Example 1) The following two types of epoxy resins, phenolic compounds, curing agents and curing accelerators were used as raw materials for epoxy resin compositions. Epoxy resin 1: a bisphenol A type epoxy resin having an epoxy equivalent of 190 [Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.] Epoxy resin 2: an epoxy equivalent of 210 and a softening temperature of about 80 ° C. Cresol novolak type epoxy resin [EPI, manufactured by Dainippon Ink and Chemicals, Inc.
CLON N680] ・ Phenolic compound: Tetrabromobisphenol A
[Use reagent] ・ Curing agent: Dicyandiamide [Use reagent] ・ Curing accelerator: 2-ethyl-4-methylimidazole [Use reagent] ・ Compound represented by the above formula (a): [Asahi Denka Kogyo Co., Ltd.] Made by company, trade name ADK STAB 522A].

As a base material, a glass cloth having a thickness of 0.1 mm [trade name: 216, manufactured by Asahi Schwebel Co., Ltd.]
L] was used.

After melt-mixing epoxy resin 1 (45 parts by weight) and epoxy resin 2 (13 parts by weight) at 130 ° C., the compound represented by the above formula (a) (0.5 part by weight) and the phenolic compound (35 parts by weight) and then 130 ° C.
For 20 minutes to obtain a first mixture.

Also, epoxy resin 1 (7 parts by weight), a curing agent (3 parts by weight) and a curing accelerator (0.06 parts by weight)
Using this roll, the mixture was kneaded at 40 ° C. to obtain a liquid second mixture.

The above first mixture was degassed under reduced pressure while being heated to 70 ° C., and the second mixture was degassed under reduced pressure while being heated to 40 ° C. Next, the first mixture and the second mixture, which were degassed under reduced pressure, were supplied to the mixer while being weighed using a gear pump so that the above-mentioned weight ratios were obtained. Next, the first mixture and the second mixture were mixed with a mixer while heating to 60 ° C. to obtain a solventless epoxy resin composition.

Next, this solvent-free epoxy resin composition is supplied to a hopper of a die coater heated to 60 ° C., and the solvent-free epoxy resin composition in the hopper is discharged from a lip portion of the die coater to form a base. The material was applied to one side of the material and then heated with a heater at 70 ° C, and then heated at 180 ° C for 2 minutes with a floating dryer to obtain a prepreg.

Further, ten prepregs thus obtained were stacked,
After laminating 18 μm thick copper foil on both sides, 170
Heating and pressurizing under conditions of 3.0 ° C. and 3.0 MPa for 1 m in thickness
m of the copper-clad laminate was obtained.

Example 2 A compound represented by the above formula (b) [trade name: ADK STAB PEP-24G manufactured by Asahi Denka Kogyo Co., Ltd.] in place of the compound represented by the above formula (a)
A prepreg and a copper-clad laminate were obtained in the same manner as in Example 1 except for using.

Example 3 Instead of the compound represented by the above formula (a), a compound represented by the above formula (c) [trade name ADK STAB HP-10 manufactured by Asahi Denka Kogyo Co., Ltd.] was used. Except for this, a prepreg and a copper-clad laminate were obtained in the same manner as in Example 1.

(Example 4) A compound represented by the above formula (d) [trade name: Adekastab C manufactured by Asahi Denka Kogyo Co., Ltd.] was used instead of the compound represented by the above formula (a). In the same manner as in Example 1, a prepreg and a copper-clad laminate were obtained.

Example 5 Instead of the compound represented by the above formula (a), a compound represented by the above formula (e) [trade name: ADK STAB A0-20 manufactured by Asahi Denka Kogyo Co., Ltd.] was used. Except for this, a prepreg and a copper-clad laminate were obtained in the same manner as in Example 1.

Example 6 Instead of the compound represented by the above formula (a), a compound represented by the above formula (f) [trade name ADK STAB A0-30 manufactured by Asahi Denka Kogyo Co., Ltd.] was used. Except for this, a prepreg and a copper-clad laminate were obtained in the same manner as in Example 1.

Example 7 Instead of the compound represented by the above formula (a), the compound represented by the above formula (g) 2,
A prepreg and a copper-clad laminate were obtained in the same manner as in Example 1 except that 6-di-tert-butyl-p-cresol [using a reagent] was used.

Example 8 Instead of the compound represented by the above formula (a), the compound represented by the above formula (h)
A prepreg and a copper-clad laminate were obtained in the same manner as in Example 1 except that 6-di-tert-butyl-4-ethylphenol [using a reagent] was used.

Comparative Example 1 A prepreg and a copper-clad laminate were obtained in the same manner as in Example 1 except that the compound represented by the formula (a) was not used.

(Comparative Example 2) Except that the compound represented by the above formula (a) was replaced with a general antioxidant, 3-tert-butyl-4-hydroxyanisole [using a reagent], A prepreg and a copper-clad laminate were obtained in the same manner as in Example 1.

(Evaluation and Results) The degree of discoloration of the prepregs obtained in Examples 1 to 8 and Comparative Examples 1 and 2 was visually evaluated. In the case of transparency, △ indicates light yellowish brown color and × indicates yellowish brown color.

The heat resistance of the copper-clad laminates obtained in Examples 1 to 8 and Comparative Examples 1 and 2 was measured. The method was measured at 230 ° C according to JIS standard C6481.
Indicates that no abnormalities such as blistering and peeling were observed, and x indicates the case where abnormalities such as blistering and peeling were observed.

As shown in Table 1, it was confirmed that the prepreg obtained in each of the examples was a prepreg which was less likely to turn yellow-brown than the prepreg obtained in Comparative Example 1. Further, the copper-clad laminate obtained in each of the examples is the same as that of the comparative example 2.
It was confirmed that the heat resistance was better than that of the copper-clad laminate obtained in the above. That is, it was confirmed that the use of the epoxy resin composition according to the present invention provided a prepreg which was not easily discolored to yellow brown without lowering the heat resistance of the obtained laminate.

[0059]

[Table 1]

[0060]

The epoxy resin composition for a laminate according to the present invention contains at least one compound selected from the group represented by the above formulas (a) to (h). The resulting prepreg is less likely to turn yellow-brown without lowering the heat resistance of the resulting laminate.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Fukuhara 1048 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Works, Ltd.

Claims (9)

[Claims] 1. An epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (a). An epoxy resin composition for a laminate, comprising a compound. Embedded image 2. An epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (b): An epoxy resin composition for a laminate, comprising a compound. Embedded image 3. An epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent and a curing accelerator, the epoxy resin composition is represented by the following formula (c). An epoxy resin composition for a laminate, comprising a compound. Embedded image 4. An epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (d). An epoxy resin composition for a laminate, comprising a compound. Embedded image 5. An epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent and a curing accelerator, the epoxy resin composition is represented by the following formula (e). An epoxy resin composition for a laminate, comprising a compound. Embedded image 6. An epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (f). An epoxy resin composition for a laminate, comprising a compound. Embedded image 7. An epoxy resin having an average of two or more epoxy groups in a molecule and a phenolic hydroxyl group in a molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (g): An epoxy resin composition for a laminate, comprising a compound. Embedded image 8. An epoxy resin having an average of two or more epoxy groups in the molecule and a phenolic hydroxyl group in the molecule.
In a substantially solvent-free epoxy resin composition for a laminate containing a phenolic compound having at least one phenolic compound, a curing agent, and a curing accelerator, the epoxy resin composition is represented by the following formula (h): An epoxy resin composition for a laminate, comprising a compound. Embedded image 9. The epoxy resin composition according to claim 1, wherein the curing agent is dicyandiamide.